Sound and picture changeover system



April 20, 1954 J. F. BYRD E-r AL SOUND AND PICTURE CHANGEOVER SYSTEM` Filed June 10, 1952 IN V EN TORS. JOHN F'. BYRD JAMES D. PHYFE MMM .'RZVEX Patented Apr. 20, 1954 y SOUND AND PICTURE CHANGEOVER SYSTEM `.John Byrd, Ashland, and 'James 12D. `IPhyfe, Moorestowm N. J., assignors to Radio .Corpo-- ration of America, `a corporationofDelaware Application June 10, 1952, SerialKNo. 292,761

Claims. 1

This invention relates to combined-sound and picture changeover systems, and particularly to an all-electric-system for ychanging over both picture and sound from one sound picture projector to another by a singlel push button located at each of the projectors.

Changeover systems for sound picture projectors in theater -film projection booths are well-known, many of Vthese systems using an interconnecting rod between projectors on the front wall ofthe booth, while others use complex electrical controls to perform the functions ofthe present invention. One prior system is disclosedand claimed in J. D. Vl-"hyfe U. S. Patent No. 2,440,184 of April 20, `1948. The present systexnfutilizes a momentary type of push button switch at each projection machine which rst shorts the audio input Ato the power amplier so that subsequent connections and disconnections do not create a disturbance in the current-tosound wave transducers or loudspeakers. Further movement of the button connects a power source to the actuating relays for connecting the output of an incoming sound reproducer to the power amplifier. VIt also clears all unwanted circuits Iby opening the output circuits oa-ll the reproducers not being used. In addition to switching fthe sound between Vreproducers, the system also'simultaneously operates the picture dowsers by energizing the dowser actuating solenoids in the well-known manner. It is not limited to only two projecting machines, but is suitablefor controlling any number.v4 Also, any particular sound portion of a sound record may be deleted VVby a vpartial actuation of any control button.

The principal object of the invention, therefore, `is to facilitate the changeover of sound andpcture between multiple sound picture projectors.

Another object of the invention is to provide an improved al1-electric changeover systemwhich utilizes momentary push buttons at each projector.

A further object of the invention is to provide van all-electric sound and picture changeover system which is adaptable for more than two sound picture projector units.

A still further object of the invention lis to provide yan improved all-electric sound and picture changeover system which is particularly economical to manufacture, install, and maintain.

Although the novel 'features which are .believed t0 be characteristic of this invention will be pointed out with -particularityin-the appended claims, the-manner -of its lorganization and the mode of -its operation will be better understood by referringto the following description, read inconjunction with the accompanyingdrawings, forming af-pa-rt hereof, in whichthe single figure is a combination schematic and diagrammatic drawing of the system vembodying the invention.

As shown in the drawings, three sound current generators, suchas soundheadunits 5,'6, and 1, are indicated, Vthesevunits including the necessary exciter lamps and preampliers, which are required Vto translate the soundtrack on a motion 'picture nlm vto electrical currents. It A-is understood, of course,-that other sound sources may be used as well as sound-nlm. The output of soundhead No. '-1 is'connected overa Volume control unit-i9, switchcontacts II when closed, and conductors (I2-to a power amplifier unit I3. which may -feed loudspeakers or sound recorders. The output of fsoundhead unit No. 2 is connected over volume control unit I5, contacts vIt when closed, conductors l'I, and conductors I2 to arnplier I3. rSoundhead Vunit No. 3 is connected over volume control unit I9, contacts 20 when closed, conductors 2-l, Vand conductors I2 to power lamplifier I3. Additional units could be added, if desired, --by paralleling the circuits.

The soundhead unit No. lis controlled by a momentary push Abutton switch shown genera-ily at 23 soundhead No. 2 is controlled by a momentary push button switch shown generally at 24; and soundhead No.- 3 is controlled by a momentary push button switch shown generally vat 25. Each switch lhas respective hand or nger actuating buttons 26, 21, and 28. The norma-l'position of switches 23, 24, and-25 are as shown in the drawings. The switches are biased to the positions shown-'in any well-known manner, lThe input to amplier l'3 is short-circuited by a contact 29 at switch v23 lwhen closed over conductors 3G. A similar contact 3! at switch 24 shortcircuits the input to ampliiier i3 over conductors 32, and contact 33 of switch'25 will short-circuit the input of amplifier I3 over conductors 34 when the contact is closed. The left-hand contacts 35, 36, and .31 of the respective switches are normally closed, and control the reset coils 39, ci), and 4|, respectively, of latching relays shown generally at ,44, 4,5, and 46. All of these relays and vswitches are shownyin the drawing in reset or normal positions.`

A source of energy, such as .an -volt alternating ourrentsupply, may be connected to the system at terminals 48, A pilot light 50 is con nected to this supply over conductor 5|, conductor 52, contact 53 when latching relay 44 is energized by its coil 55, conductor 56, and conductor 51. Similarly, the pilot light B is energized over conductor conductor 6|, contact 62 when coil 83 of latching relay 45 is energized, conductorf64, and conductorI 51. Similarly, pilot light 166 `.isfcnergized over conductor 5|, conductor 61, contact 68 when closed by the energization of coil 89 of latching relay 46, conductor 10, and conductor 51. These pilot lamps show which particular machine `is'in Aoperation at any time.

Assume it is desired to connect soundhead No. 1 for reproduction and actuate the dowser for its picture projector, then switch 23 is momentarily actuated. The switch contacts of switch 23 are so adjusted that the nrst action is the closing of contact 29, which short-circuits the input to amplier I3. The next action is the breaking of contact to prevent energization of its reset coil 39. Next, further movement of the switch will make contacts 12 and the making of these contacts will connect energy from the 115- volt source connected at 48 over conductor 5i, conductor 13, closed contacts 12, conductor 15, coil 55, conductor 18, and conductor 51. Latching relay 44-is thus energized, and when actuated, it closes contact 53 to energize pilot light 5G over the circuitjust described and closes contacts Il to connect the output of soundhead No. 1 to power amplifier i3.

Assuming that soundhead No. 2 was previous- 1y operating, then power will be also supplied over contacts 12, conductor ifi, contact 36 at switch 24, conductor 13, reset coil of latching relay 45, conductors Bland conductor 51. Thus, the contacts I6 will be broken along with the contact of pilot vlight Sii. If we assume that soundhead No. 3 was previously operating, then reset coil 4| 4of latching relay 46 is energized over contacts 12, conductor 18, conductor 8|, contact 31 at switch 25, conductor 82, coil 4|, conductor 83, and conductor 5l'. Thus, the momentary actuation of any particular switch rst shorts out the input to amplifier I3, then connects the incoming soundhead to the power ampliiier, and then disconnects the outgoingsoundhead and clears all unwanted. circuits.

For instance, when switch 24 is actuated, contacts 85 are made, which will energize reset coil 39 of soundhead No. l over conductor 5|, conductor 86, left-hand contact 85, conductor 18, contact 35, conductor 81, reset coil 39, conductor 16, and Iconductor 51. This will also be true if switch 25 were actuated, closing contacts 89, the left-hand contact energizing the coil 39, while both contacts would supply power to the coil 69 over conductor 9|, coil 89, conductor 83, and conductor 51. The closing of both contacts 85 of switch 24 will energize the actuating coil 63 of latching relay over the two contacts 85, conductor 92, coil 83, conductor B0, and conductor 51. After any of switches 23, 24, and 25 are released, their short-circuiting contacts 29. 3|, and 33 are broken and the respective soundhead is connected to amplifier |3.

There is thus provided a very simple system for not only changing sound without disturbing switching noises in the loudspeakers, but also for actuating the respective dowsers which have a pair of solenoids similar to the latching relay coils and are energized over respective conductors 94, 55, and 96. Since the short-circuiting contacts 29,3I, and 33 are made before the con- 4 tacts 35, 36, and 31 are broken or contacts 12, 85. and 89 are made, the deletion of any portion of any sound record in any machine may be accomplished by partially actuating any button so as to only make its short-circuiting contact.

We claim:

1. A changeover systemcomprisingaplurality of soundicurrent generators, an amplifier connectable to the outputs of all of said generators, `electrically operative switches each having a pair of windings and a plurality of contacts for connectingand disconnecting the outputs of said generators to and from said ampliiier, a power supply, a .manually operative switch at each of said. generators, Aand circuit means interconnecting saidelectrically operative switches, said power supply.,` and said manually operative switches, each of said manually operative switcheshaving a pair of normally open contacts which are iirst closed for short-circuiting the input of said amplifier, apair ci' normally closed contacts which are then opened to prevent the connecting of one of said windings of said electrically operative rswitch to said power supply, and a plurality of contacts which are then made for connecting said power supply to the other winding oi' said electrically operative switch associated with said manually operative switch and one of the windings of each of said other electrically operative switches.

2. A changeover system in accordance with claim l, in which electrically operative relays corresponding in number to said electrically operative switches are provided, said .electrically operative relays each having a pair of windingsconnected in parallel with the pair of windings on a respective electrically operative switch.

3. A changeover system in accordance with claim l, in which each of said electrically operative switches is a latching relay with an energizing winding and a reset winding.

4. A changeover system in accordance with claim 1, in which a pilot light is provided for each. generator, together with circuit means from Lg said manually operative switches and said supply for energizing the pilot light for an operating generator.

5. A changeover system comprising a plurality of sound generators, an amplifier connectable toall of said generators, a power supply, electrically operative switches each having a pair of windings, said switches corresponding in number to said generators each of said switches being associated with a particular generator, for connecting its associated generator to said amplifier with one energization of one of said windings by saidl supply and disconnecting all of `said other generators from said amplifier with another energize.- tion of one winding on each of said other switches by said supply, plural contact manually operative switches corresponding in number to said generators and said electrically operative switches, and circuit connections connecting saidy supply, said amplifier, and said electrically operative switches, one contact on each or" said manually operative switches-being made first before its other contacts are made for short-circuiting said amplifier, themaking of said other contacts energizing the winding of its corresponding electrically operative switch to `connect its corresponding generator to said amplifier, and energizing one winding of each of all other electrically operative switches to disconnect any other generator connected to said amplifier from .said amplifier.

6. A changeover system in accordance with claim 5, in which electrically operative relays corresponding in number to said electrically operative switches are provided, said electrically operative relays each having a pair of windings connected in parallel with the pair of windings on a respective electrically operative switch.

7. A changeover system in accordance with claim 5, in which said plural contact manually operative switches each have four make and break contacts, three of said contacts being normally open and one closed, actuation of a switch closing first one contact to short-circuit the input of said amplifier, then opening its normally closed Contact to prevent actuation of its corresponding electrically operative switch to disconnect said corresponding generator from said amplifier, and then closing its remaining two contacts to connect said supply to its corresponding electrically operative switch to energize said switch and connect said corresponding generator to said amplifier and connect said other electrically operative switches to said supply over their normally closed contacts to disconnect any previously connected generator from said ampli- Iier.

8. A changeover system in accordance with claim 7, in which each of said electrically operative switches is a latching relay with an energizing winding and a reset winding.

9. A changeover system comprising a plurality of current generators, an amplier, an electrically operative switch for each current generator, a manually operative switch for each electrically operative switch, a power supply, a circuit connecting said supply and each of said manually operative switches and said electrically operative switches, the closing of any one manually operative switch connecting its respective electrically operative switch to said supply for actuating said electrically operative switch in one direction and connecting said lother electrically operative switches to said supply for actuating said other electrically operative switches in another direction, and a circuit connecting each of said manually operative switches and said amplifier for short-circuiting the input to said amplifier upon actuation of any one of said switches, said electrically operative switches acting to connect each of said generators to said amplifier at mutually exclusive times.

10. A changeover system in accordance with claim 9, in which a pilot light is provided for each electrically operative switch and energized when said electrically operative switch is actuated in one direction, said electrically operative switches being latching relays.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,036,306 Soons Apr. 7, 1936 2,106,957 Nielsen Feb. 1, 1938 2,181,513 Kurtz@ Nov. 28, 1939 2,277,207 Chenoweth et al. Mar. 24, 1942 2,305,681 Dunning Dec. 22, 1942 2,542,188 Gates Feb. 20, 1951 

